As I am writing this, I am listening to Mozart. More specifically the Queen of the Night aria out of The Magic Flute. It races through C # minor. One moment clear and in the air, the next, grounded and dominant.
My subject for today is another Queen of the Night. The invasive species of cactus that we have at Swebeswebe Nature Reserve, Cereus jamacaru. They were brought to our shores from Mexico and the USA, probably because it makes a very good hedge and a good garden subject in arid areas with poor soils.
This cactus really is attractive. It stands over 6m tall under ideal conditions and reproduces both with seed and vegetatively. The flower, a big, white trumpet-like structure, only opens at night and sometimes during overcast days.
The problem is that our baboon population loves them. The fruit is edible, and the pin-size seeds grow very effectively in loose mountain soils. Wherever the baboons break the plants, new ones will grow, as they root very easily as well.
We control the spread of these plants with a well-proven method of drilling a hole into the plant with a homemade hand drill. The hole is then filled with a herbicide called MSMA. In areas where the plant infestations are great enough, biological control mechanisms like mealy bugs and stem borer beetles can be used to combat their spread. These insects are bred to be sterile and pose no threat to the local vegetation, but they need to be near their host to effectively combat its spread.
We have another approach. It is called: “Climb the mountain with all your tools and declare war on the alien plants”. It is dangerous work. Apart from the very real chance of twisting an ankle on the steep slopes, slipping and falling is a possibility. And then we work with herbicides that can potentially be problematic to humans, thus the gloves and other protective gear.
The video shows the method of drilling and filling the hole with herbicide. This will slowly kill the plant by inhibiting the cell division and energy storage of the plant. It turns grey, and then brown. Then it falls over and becomes compost.
When all is said and done, the combatants will retreat to their homes. They will be tired, thorn pricked and footsore. And in the mood for a glass of something comforting with Mozart somewhere playing in the background.
Written by André Nell
Manager of Swebeswebe Nature Reserve